In the recent field of endoscopic minimal invasive surgery and also in many technical sectors, it is frequently difficult to work with manual dexterity in inaccessible areas. For that reason many appliances have been developed to execute special gripping and manipulating work. The disadvantage of those special tools is however that the appliances must repeatedly be exchanged as the operation proceeds. It would thus be an advantage if the operator could work with a miniature artificial hand in inaccessible areas.
The invention deals with the problem of providing the operator with a manipulator which
directly takes up the movements of the human arm, hand and fingers and PA1 transmits these movements directly to an identical unit in terms of form and function, which PA1 can be pushed through narrow channels, such as the trocars of modern minimal invasive surgery into the site of operation, where it functions in the same way as a hand and is simultaneously PA1 simply constructed so that it is easy to wear.
Appliances which take up the movement of human movements of the remote control of gripping devices in robots are already known. U.S. Pat. No. 4,302,138 and French Patent Number 2,416,094 show an appliance which measures the movement of the human hand either directly by electric sensors situated in the hand or via mechanical rods to electric sensors further away from the hand. These sensors pass on the electric signal to control a gripping device.
Appliances which function like a human hand in terms of form and function are already known. None, however, are controlled directly by the human limbs in a purely mechanical fashion. In that respect U.S. Pat. No. 4,834,761 shows an appliance which is operated by means of a system of hydraulically acting pistons and the movement of which is transmitted to the fingers by means of cords (strings) using pulley constructions. U.S. Pat. No. 5,092,646 shows an appliance powered by servo-motors in which a whole finger of one hand is bent via a double winch construction and stretched via a spiral spring using stretch cords. In U.S. Pat. No. 4,986,723 the stretch movement is also executed with the aid of a spiral spring and the bending movement with the aid of a pulley. U.S. Pat. No. 4,921,293 also shows fingers moved by means of pulley constructions.
In the aforesaid appliances, the control signals from the control unit are transmitted to the gripping device electrically. Mechanical transmission is known in DE-AS-2048563, in which a firmly installed working arm is moved via pulleys. The movement executed by the appliance arm, however, is not taken up and transmitted from the arm of the operator, but by a control arm which has to be moved by that person. In the case of that appliance, the operator must continually consider how to steer the control arm in order to bring the working arm into the position required.
The same occurs in the idea presented in DE-2939452, which also concerns not a portable but a fixed appliance. Both arms have a direct swivel connection via an axle so that swivelling the control arm leads to a corresponding swivel movement of the secondary arm. Because of that design, however, the appliance cannot be used to control movements through a narrow channel, such as that of a trocar. That, however, is the aim of one of the features of the invention described here. The two parallelograms shown in specification DE-2939452 are integral components of the arms without which no movement whatsoever can be executed. Movement transmission is achieved by pushing or pulling wires or threads. The levers or pantographic elements serve only to correct the path of these wires or threads and are not integral parts of the appliance sections. Movement of the appliance sections is also possible without the above elements, so that they are used only to adjust the Bowden cable movement. That adjustment is important, e.g., if a new and smaller distal hand is to be attached to an existing proximal one. Special movements can thereby be attained in the manner specified below.
All these prior appliances are unsuitable for use in inaccessible areas with small dimensions--such as the human abdominal cavity--owing to their size and complicated structure.